<template>
    <div>
        <h3>当前求和的值为:{{sum}}</h3>
        
        <select v-model.number="n">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
        </select>
        <button @click="increment">+</button>
        <button @click="decrement">-</button>
        <button @click="incrementOdd">当前求和为奇数再加</button>
        <button @click="incrementWait">等一等再加</button>
    </div>
</template>

<script>
    export default {
        name:'Count',
       data() {
           return {
               sum:0,
               n:1
           }
       },
       methods: {
           increment(){
               this.sum += this.n
           },
           decrement(){
                this.sum -= this.n
           },
           // 奇数再加
           incrementOdd(){
               if(this.sum %2){
                    this.sum += this.n
               }
           },
           incrementWait(){
               setTimeout(()=>{
                   this.sum += this.n
               },1000)
           },
       },
    }
</script>

<style>
    button{
        margin-left: 10px;
    }
</style>